Avaliação de um reator eletroquímico utilizando eletrodo DSA (Ti/Ru0,3Ti0,702) na degradação do corante AR-88.

Abstract

The effluents from textile industries when untreated, are highly polluting due to the presence of dyes, among which we can cite those that link the azo type (Rl-N = N-R2). These compounds, known azo dyes account for approximately 70% market share of this material in the textile industry which increases the environmental concerns, because without appropriate treatment of effluents containing them, because of their low degradability recalcitrance and therefore has the effect of cumulative pollutant . The objective of this study was to evaluate the efficiency of direct oxidation (electrochemical) and indirect (chemical) of acid red dye using an electrochemical cell electrode configuration and cross-oxide semiconductor type DSA (Ti / Ru_0,3 Ti_0,7 0_2) for the degradation of a synthetic textile effluent. DTR, comparing to existing theoretical models - first, to characterize the electrochemical cell used, a dimensional analysis has been proposed in which an empirical model for the efficiency of mass transfer, followed by the study of the distribution of the residence time was performed. In the electro oxidation process was investigated the influence of the main operating parameters such as oxidation potential, and used amount of chloride feed stream on the rate of reduction of the concentration of the dye. At the same time, we assessed whether the process of electrochemical degradation of dye was governed by charge transfer (faradaico control) or by convective diffusion to a reactor type PFR. It can be concluded that the process of electrochemical degradation is governed by faradaico control. Moreover, it was found that after 20 minutes of electrolysis, there was obtained 92.64% degradation of the dye applied to a difference of potential (DDP) 3.5V, reaching almost 100% degradation of the dye to the (ddp) of 5.0V. Varying the concentration of sodium chloride resulted in a small change in the degradation rate for the same electrolysis time of 1 hour. A 1st order kinetic model was presented as suitable for characterizing the process of degradation of acid red dye. Regarding the analysis of TOC, we noticed a decrease of 32% to a potential of 5.0V.